Include

[130CC]

Hi and welcome
Fuel filter is easy and here is the service to clear up the questions about fuel drain.

ELEMENT - FUEL FILTER
Service repair no - 19.25.07
Remove
1. Release fixings and remove battery cover.
2. Disconnect battery negative lead.
3. Raise rear of vehicle.
WARNING: Support on safety stands.

4. Release fixing and remove fuel filter cover.
5. Clean area around fuel filter.
6. Disconnect multiplug from filter element.
7. Remove fuel filter element.
Refit
8. Clean fuel filter and mating face.
9. Fit new fuel filter element and connect multiplug.
10. Position fuel filter cover and secure with fixing.
11. Remove stand(s) and lower vehicle.
12. Reconnect battery negative lead.
13. Fit and secure battery cover.

Also here is the adjustment to the transfer case to make the adjustment to the switch in the Transfer case

Service repair no - 41.20.36
Adjust
NOTE: This procedure is only necessary
for switches fitted with a locknut in place
of the threaded spacer.
1. Move differential lock selector fork to differential
locked position.
2. Connect a 12V test lamp and battery to
differential lock warning lamp switch.
3. Screw switch in until test lamp is illuminated then
screw switch in a further 1/2 turn; tighten locknut.
4. Disengage differential lock, check that test lamp
is extinguished.
5. Remove test lamp.

Easy as.
Adam